The invention relates to an apparatus for open end friction spinning having two adjacently arranged friction rollers driven in the same rotational direction which define a yarn formation zone comprising a wedge-shaped gap. An inlet and opening device is provided for the fiber material to be spun including a fiber feed channel for feeding fibers to the wedge-shaped gap which is disposed at a sharp angle with respect to the gap. A withdrawal device for drawing the spun yarn in the longitudinal direction of the wedge-shaped gap and opposite the inlet direction of the fiber feed channel is provided.
With a known construction of the above mentioned kind (disclosed in European Patent Published Unexamined Application No. 0062404) both of the rollers are disposed horizontally adjacent one another so that the wedge-shaped gap formed thereby also extends horizontally. The inlet and opening device as well as the withdrawal device are disposed on the same side with respect to the end face of the rollers. With this known construction the individual elements are difficult to service because they are accessible only with great difficulty. This is true as well not only for the extending wedge-shaped gap which is difficult to observe, but also for the inlet and opening device and the withdrawal device which must be arranged in a very small space adjacent one another. This device is therefore also not suitable to accommodate servicing by means of an automatic traveling servicing device which, for example, carries out a start or piecing operation and/or a cleaning of the rollers, especially in the region of the wedge-shaped gap.
An object of the present invention is to construct an apparatus of the above mentioned kind wherein the individual elements are disposed in a serviceable and easily automated arrangement with respect to one another.
This object is attained in the provision of an apparatus having rollers that are arranged to extend essentially vertically. The inlet and opening device is arranged below the rollers and the withdrawal device is arranged above the rollers. Means for turning the yarn are first disposed to guide the yarn downwardly from the wedge-shaped gap and then back up to the withdrawal device.
This construction results, on the one hand, in a very compact construction arrangement. On the other hand, all of the elements for a servicing procedure are easily accessible and are also disposed for access by servicing devices of an automatic machine moving along the spinning machine.
In advantageous embodiments of the invention, it provided that the yarn forming position of the wedge-shaped gap is disposed at the servicing side of the spinning machine. This position is covered by means of a movable housing part which includes at least a part of the fiber feed channel. Thereby, the two rollers and also the region of the wedge-shaped gap can be exposed for a servicing process in a simple manner.
In order to accommodate different spinning conditions, it is provided according to the advantageous developments of the present invention that the means or mechanism for turning the yarn is adjustable in the direction of the plane of the wedge-shaped gap. The plane of the wedge shape gap extends through the gap is perpendicular to a plane passing through the area of rotation of the friction rollers. In this manner it can be assured that with different yarns, the yarn withdrawal is first in the direction of the wedge-shaped gap plane and then thereafter is turned. The turning of the yarn extension toward the withdrawal out of the wedge-shaped gap has further the advantage that thereby a twist block is created. The produced spinning twist in the yarn is thereby essentially reduced in the region between the wedge-shaped gap and the turning position in a controllable manner.
In further embodiments of the invention, it is provided that the first turning position at the connection with the wedge-shaped gap is formed by a turning roller. Advantageously the turning roller is provided with a guide groove for the yarn. With the help of this type of turning roller, it is possible to turn the yarn also laterally out of the wedge-shaped gap plane.
In advantageous embodiments of the invention, it is provided that a yarn guide channel connects to the turning roller. It is also advantageous that the yarn guide channel be adjustable in its inclination with respect to the wedge-shaped gap. Thereby, the effect of the blocking of the twist from the turning position can be controlled.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.